Pipe-derrick



UNITED STATES PATENT @EETQE.

GEORGE CORBE'IT, OF BRADFORD, PENNSYLVANIA.

PIPE-DERRICK.

SPECIFICATION forming part of Letters Patent No. 346,466, dated August3, 1886.

(No model.)

To all whom it may concern:

Be it known that I, GEORGE CORBETT, a citizen of the United States,residing at Bradford, in the county of McKean and State of Pennsylvania,have invented certain new and useful Improvements in Pipe-Derricks; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

The object of my invention is to construct a derrick for Artesian wells,signal-towers, electric-light supports, or other similar purposes, ofiron pipe, so that it will be strong, offerbutlittle resistance towinds,and be readily erected or taken down.

I attain the object of my invention by the devices shown in theaccompanying drawings, in which- Figure 1 is a view, partly in section,of one of the corner sockets. Fig. 2 is a view in section of the topsocket. Fig. 3 is a View of the top portion of the derrick. Fig. 4 is aview of one of the hooks on the ends of the tierods. Fig. 5is a view ofthe bottom socket. Fig. 6 is a View of a modified form of corner socket,and Fig. 7 is a view of the lower part of the derrick.

The invention will be described as it will be used on an ordinaryderrick for an oil-well. Such derricks are generally seventy-two feethigh, twenty feet square at the base, and two and a half feet square atthe top, the first girt of the derrick being nine and a half feet(measured on the incline) from the floor, and the other girts beingseven feet eight inches apart, (measured also on the incline.) Thecorner sockets must be all made to fit the desired slant of the legs ofthe derrick and girts.

The bottom socket is designated by the letter A, and is constructed ofcast or malleable iron,with a square base, a, to rest on the floor B ofthe derrick. Projecting from said base a is the stem a,which has ashoulder, of. The stem at is two inches outside diameter,so as to form astud for the two-inch pipe 0. For the lower part of the derrick Irecommend that a second pipe two and a half inches inside dia'meter, D,be placed over the pipe 0. The first length of pipe may be either nineand a half feet, seventeen feet two inches, twentyfour feet four inches,or thirty-one feet six inches long. It should be so cut that its endwill come in the middle of one of the corner sockets E. Said cornersocket E is made as shown in Fig. 1, having the two set-screws F F andtwo side projections, G, (only one of which is shown in the drawings.)The side projections,G,are at right angles to each other. Above andbelow each projection is a loop or eye to receive the hook I, Fig. 4,ofthe tie-rod J.

The tierods J J stretch from the corner of one girt, k, to an upper orlower diagonallyopposite corner, and are tightened by the turnbuekles LL, of which there is one on each tierod. The tie-rods to the first storyare fastened to the derrickfloor B, as shown in Fig. 7.

The corner socket shown in Fig. 1 is made so that it slips over thepipe. Then the pipe is long enough, it goes through the socket E, andwhen fitted to its place the set-screws F F are firmly tightened; but ifthe pipe is not long enough to reach the next girt it is cut off, so asto reach to the center of a corner socket, E.

It is desirable, but not essential, that not more than one or two of thelegs should make ajoint at the same girt.

When short pieces of pipe are used,the corner socket is constructed asshown at M, Fig. 6, which differs from E, Fig. 1, only in being madewith studs m m and shoulders m m at top and bottom to receive the pipe0.

The corners at the top of the derrick are terminated by the top sockets,N, which have a top plate, at, and a stud, n, and two eyes, H, at rightangles to each other. A bolt, 0, passes through the upper plate, 12 tofasten the top block, P, which supports the corner pulley, Q. A woodenplug may be driven in the hollow of n, to hold the bolt 0 in place untilthe nut is attached to it.

If it were desired to make a derrick threelegged, the eyes H andprojections G on the sockets would be (as to each upper and lower pair)at angles of sixty degrees to each other, and corresponding changes inthe angles would be made if more than four legs were desired.

What I claim as my invention isl. A derrick made of pipe resting uponthe base-plates A, with girts united to the legs by corner sockets, andthe tops of the legs 5. The corner socket M, provided with the studs m,the shoulders m",the side projections, 1 G, and the eyes H,substantially as shown and described.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE COBB ETT.

Witnesses:

JAMES 0. Boston, LILLIAN E. HOFFMAN.

